Cumulative Input Function Method for Linear Compartmental Models and Spectral Analysis in PET

Simončič, Urban; Jeraj, Robert

doi:10.1038/jcbfm.2010.159

Cited by 8 publications

(6 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In our study, the parameters K 1 , k 2 , k 3 and v b were not statistically significant different between all control and operated regions. This observation might correspond to the reported decrease of stability of K 1 , k 2 , k 3 compared to K i , NLR [ 31 , 34 , 35 ]. Cook et al stated that due to possible limitations of the model, the physiological significance of parameters k 2 and k 3 is not meaningful in relation to the mineralized skeleton [ 35 ].…”

Section: Discussionsupporting

confidence: 71%

Evaluation of a short dynamic 18F-fluoride PET/CT scanning method to assess bone metabolic activity in spinal orthopedics

et al. 2015

View full text Add to dashboard Cite

ObjectiveA complication after spinal fusion surgery is pseudarthrosis, but its radiological diagnosis is of limited value. 18F-fluoride PET with its ability to assess bone metabolism activity could be of value. The goal of this study was to assess the clinical feasibility of calculating the static standardized uptake value (SUV) from a short dynamic scan without the use of blood sampling, thereby obtaining all dynamic and static parameters in a scan of only 30 min. This approach was tested on a retrospective patient population with persisting pain after spinal fusion surgery.MethodsIn 16 patients, SUVs (SUVmax, SUVmean) and kinetic parameters (K1, k2, k3, vb, Ki,NLR, K1/k2, k3/(k2 + k3), Ki,patlak) were derived from static and dynamic PET/CT scans of operated and control regions of the spine, after intravenous administration of 156–214 MBq 18F-fluoride. Parameter differences between control and operated regions, as well as between pseudarthrosis and fused segments were evaluated. SUVmean at 30 and 60 min was calculated from kinetic parameters obtained from the dynamic data set (SUVmean,2TCM). Agreement between measured and calculated SUVs was evaluated through Bland–Altman plots.ResultsOverall, statistically significant differences between control and operated regions were observed for SUVmax, SUVmean, Ki,NLR, Ki,patlak, K1/k2 and k3/(k2 + k3). Diagnostic CT showed pseudarthrosis in 6/16 patients, while in 10/16 patients, segments were fused. Of all parameters, only those regarding the incorporation of bone [Ki,NLR, Ki,patlak, k3/(k2 + k3)] differed statistically significant in the intervertebral disc space between the pseudarthrosis and fused patients group. The mean values of the patient-specific blood clearance rate differed statistically significant between the pseudarthrosis and the fusion group, with a p value of 0.011. This may correspond with the lack of statistical significance of the SUV values between pseudarthrosis and fused patients. Bland–Altman plots show that calculated SUVmean,2TCM values corresponded well with the measured SUVmean values.ConclusionThis study shows the feasibility of a 30-min dynamic 18F-fluoride PET/CT scanning and this may provide dynamic parameters clinically relevant to the diagnosis of pseudarthrosis.

show abstract

Section: Discussionsupporting

confidence: 71%

Evaluation of a short dynamic 18F-fluoride PET/CT scanning method to assess bone metabolic activity in spinal orthopedics

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Model equations in Eq. have been solved analytically and the PET measurement S(t) has been evaluated by using a cumulative representation of the IDIF and a variable delay t d between the input function and tissue signal.…”

Section: Methodsmentioning

confidence: 99%

Comparison of DCE-MRI kinetic parameters and FMISO-PET uptake parameters in head and neck cancer patients

Simončič

Leibfarth²,

Welz

et al. 2017

Med. Phys.

Self Cite

View full text Add to dashboard Cite

PurposeTumor hypoxia is a major cause of radiation resistance, often present in various solid tumors. Dynamic [18F]‐fluoromisonidazole (FMISO) PET imaging is able to reliably assess tumor hypoxia. Comprehensive characterization of tumor microenvironment through FMISO‐PET and dynamic contrast enhanced (DCE) MR multimodality imaging might be a valuable alternative to the dynamic FMISO‐PET acquisition. The aim of this work was to explore the correlation between the FMISO‐PET and DCE‐MRI kinetic parameters.MethodsThis study was done on head and neck cancer patients (N = 6), who were imaged dynamically with FMISO‐PET and DCE‐MRI on the same day. Images were registered and analyzed for kinetics on a voxel basis. FMISO‐PET images were analyzed with the two‐tissue compartment three rate‐constant model. Additionally, tumor‐to‐muscle ratio (TMR) maps were evaluated. DCE‐MRI was analyzed with the extended Tofts model. Voxel‐wise Pearson's coefficients were calculated for each patient to assess pairwise parameter correlations.ResultsMedian correlations between FMISO uptake parameters and DCE‐MRI kinetic parameters varied across the parameter pairs in the range from −0.05 to 0.71. The highest median correlation of r = 0.71 was observed for the pair V b−v p, while the K 1−K trans median correlation was r = 0.45. Median correlation coefficients for the K 1−v p and the K i−K trans pairs were r = 0.42 and r = 0.32, respectively. Correlations between FMISO uptake rate parameter K i and DCE‐MRI kinetic parameters varied substantially across the patients, whereas correlations between the FMISO and DCE‐MRI vascular parameters were consistently high. Median TMR‐K 1 and TMR‐K trans correlations were r = 0.52 and r = 0.46, respectively, but varied substantially across the patients.ConclusionsBased on this clinical evidence, we can conclude that the vascular fraction parameters obtained through DCE‐MRI kinetic analysis or FMISO kinetic analysis measure the same biological property, while other kinetic parameters are unrelated. These results might be useful in the design of future clinical trials involving FMISO‐PET/DCE‐MR multimodality imaging for the assessment of tumor microenvironment.

show abstract

“…The influx rate constant K i = K 1 k 3 /(k 2 + k 3 ) was calculated from the estimated parameters. Kinetic analysis was done with custom-developed program in Matlab, which utilizes a cumulative representation of the input functions (Simoncic and Jeraj 2011) that simplifies the kinetic analysis implementation and improves its accuracy when image-derived input function is used.…”

Section: Kinetic Analysismentioning

confidence: 99%

Heterogeneity in stabilization phenomena in FLT PET images of canines

Simončič¹,

Jeraj²

2014

Phys. Med. Biol.

Self Cite

View full text Add to dashboard Cite

3′-(18F)fluoro-3′-deoxy-L-thymidine (FLT) is a PET marker of cellular proliferation. Its tissue uptake rate is often quantified with a Standardized Uptake Value (SUV), although kinetic analysis provides a more accurate quantification. The purpose of this study is to investigate the heterogeneity in FLT stabilization phenomena. The study was done on 15 canines with spontaneously occurring sinonasal tumours. They were imaged dynamically for 90 min with FLT PET/CT twice; before and during the radiotherapy. Images were analyzed for kinetics on a voxel basis through compartmental analysis. Stabilization curves were calculated as a time-dependant correlation between the time-dependant SUV and the kinetic parameters (voxel values within the tumour were correlated). Stabilization curves were analyzed for stabilization speed, maximal correlation and correlation decrease following the maximal correlation. These stabilization parameters were correlated with the region-averaged kinetic parameters. The FLT SUV was highly correlated with vasculature fraction immediately post-injection, followed by maximum in correlation with the perfusion/permeability. At later times post-injection the FLT SUV was highly correlated (Pearson correlation coefficient above 0.95) with the FLT influx parameter for cases with tumour-averaged SUV30–50min above 2, while others were indeterminate (correlation coefficients from 0.1 to 0.97). All cases with highly correlated SUV and FLT influx parameter had correlation coefficient within 0.5% of its maximum in the period of 30–50 min post-injection. Stabilization time was inversely proportional to the FLT influx rate. Correlation between the FLT SUV and FLT influx parameter dropped at later times post-injection with drop being proportional to the dephosphorylation rate. The FLT was found to be metabolically stable in canines. FLT PET imaging protocol should define minimal and maximal FLT uptake period, which would be 30–50 min for our patients. Additionally, kinetic analysis should be used when low FLT avidity is expected. Low SUVs should be treated with great caution.

show abstract

Cumulative Input Function Method for Linear Compartmental Models and Spectral Analysis in PET

Cited by 8 publications

References 15 publications

Evaluation of a short dynamic 18F-fluoride PET/CT scanning method to assess bone metabolic activity in spinal orthopedics

Evaluation of a short dynamic 18F-fluoride PET/CT scanning method to assess bone metabolic activity in spinal orthopedics

Comparison of DCE-MRI kinetic parameters and FMISO-PET uptake parameters in head and neck cancer patients

Heterogeneity in stabilization phenomena in FLT PET images of canines

Contact Info

Product

Resources

About